Rate constant measurement for the OH + OH → H2O + O reaction at 220–320 K using discharge flow/mass spectrometer/resonance fluorescence technique

The rate constant for the reaction of OH + OH → H2O + O (1a) at 220–320 K has been measured under a total pressure of 1 Torr using the discharge flow/mass spectrometer/resonance fluorescence method. The rate constant for the reaction is determined to be k1a (298 K) = (1.20 ± 0.36) × 10−12 cm3 molecule−1 s−1, and found to be negatively dependent on temperature at 220–320 K, with an Arrhenius expression of k1a = 2.7 × 10−13 exp[(446 ± 37)/T] cm3 molecule−1 s−1.